Internal Combustion Engine Having On-Board Electrolyzer And Method Of Using Same

ABSTRACT

A method and apparatus for treating the exhaust gases and improving fuel efficiency of an internal combustion engine is shown, wherein an on board electrolyzer is employed to produce hydrogen (H 2 ) and oxygen (O 2 ) that are used to maximize the fuel efficiency and minimize exhaust emissions.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of provisional patent applicationNo. 60/716,331 filed Sep. 12, 2006 and provisional patent applicationNo. 60/718,072 filed Sep. 16, 2006.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The invention relates to internal combustion engines, and moreparticularly to a method and apparatus for treating the exhaust gasesand improving fuel efficiency.

2. Description of the Prior Art

In vehicles having internal combustion engines, performance and controlof the exhaust emissions must be improved. The improvements inperformance and in the quality of the exhaust emissions can be achievedin dealing with the after-treatment, as well as in-cylinder treatment.

In the after-treatment, NOX traps have been employed to decrease theamount of NOX that is released in the exhaust gases. The amount of NOXin the exhaust from internal combustion engines may be elevated when theengine is operating lean. Lean operation of an internal combustionengine improves fuel economy by reducing the pumping losses andimproving the thermodynamic efficiency. However, the exhaust from suchengines may contain a large amount of excess oxygen for extended periodsof time and thus increase the amount of NOX in the emission system.

To control NOX emissions during lean operation, emission control devicescapable of storing NOX during lean operating conditions may be employed.Periodically, as the NOX capacity of the NOX trap is approached, theair-fuel ratio may be driven to a rich condition for a few seconds inorder to purge the NOX trap of the stored NOX and to regenerate the NOXstorage capacity of the trap.

Another of the exhaust treatments is the selective catalytic reduction.However, there are area infrastructure and safety issues that must beaddressed when dealing with this process.

Both of the processes are in need of further development. This isparticularly true when considering the EPA emission regulation regardingNOX emissions. These EPA regulations call for a reduction in NOXemissions from 1.2 g/bhp-hr. in 2007 to 0.2 g/bhp-hr. in 2010. It isbelieved that the former can be met primarily using cylindertechnologies and the latter will involve a combination of in cylinderand exhaust after-treatment technologies.

The after-treatment technology must be capable of reducing as much NOXas possible to N₂ and H₂O.

In the in cylinder treatment, it has been suggested to use small amountsof hydrogen added to the hydrocarbon fuel-air mixture to increase theefficiency or reduce the pollution of the internal combustion engine.The difficulties in using hydrogen either as the sole fuel or incombination with a conventional internal combustion engine results fromthe hydrogen being a ubiquitous and very flammable gas, so that storageincreases the hazards of operating the engine and in the generalinefficiency in generating the hydrogen such as through electrolysis onthe vehicle.

Ammonia has been mentioned as a constituent of various types of fuels inthe past, both for internal combustion engines and for jet propulsion.One such fuel is a liquid mixture of ammonias nitrate in liquid ammoniawhich is a self-sustaining fuel combination requiring no addition of anoxidant such as air. Ammonia is also used to manufacture hydrazine, awell known rocket fuel, and while ammonia does not support combustion,it will burn when mixed with oxygen in air to give a variety ofproducts, principally nitrogen and water. Mixtures of nitrous oxide andammonia in a rate of 3 to 2 will detonate with some violence yieldingnitrogen and water.

In accordance with the results of the prior art, it has been found thatas a viable alternative to hydrogen as the sole fuel for internalcombustion engines ammonia employment is a viable option. There are nolarge development costs and the price of a vehicle powered by an ammoniafueled internal combustion engine is not significantly increased. Inaddition, the fuel is presently abundant and the fuel handlingtechnology already exists and is user friendly.

Ammonia based fuels offer a great potential for universal use. Adisadvantage in using ammonia based fuels is that pure ammonia is notsuitable for use in high speed engines, as the flame speed is too slow.Also, inherent with the use of ammonia based fuels in internalcombustion engines, the initiation of combustion has caused a problem.

It has been found that by doping ammonia with environmentally friendlychemical additions, the flame speed may be improved.

Notwithstanding the disadvantages, there are many advantages to beachieved by adopting an ammonia based fuel technology. A resultanteffect is the ability of internal combustion engines which operate witha clean burn at high efficiencies and a reduction in the dependency onfossil fuels.

It has been surprisingly discovered that many of the disadvantages notedabove many be overcome by the production of an internal combustionengine wherein hydrogen (H₂) is injected from an antechamber adjacent toand in connection with the combustion chamber, a high efficiencyoxidation of NH₃ fuel can be achieved.

Accordingly, it is an object of the present invention to produce aninternal combustion engine capable of operating on an ammonia based fuelwhich effectively overcomes the above problems.

It is also an object of the invention to produce a method and apparatusfor improving the exhaust emissions of internal combustion engines.

Another object of the invention is the production of an internalcombustion engine after-treatment of the exhaust emissions therefrom.

Still another object of the invention is to produce a method andapparatus for treating the exhaust emissions by the introduction ofhydrogen as a reductant in a lean NOX trap for converting N0₂ to N₂.

SUMMARY OF THE INVENTION

The above objects may typically be achieved by a system for treating theexhaust emissions comprising internal combustion engine including anexhaust gas converter for capturing NO₂; a source of hydrogen; means fordirecting the hydrogen to the exhaust gas converter for converting theNO₂ therein to N₂; and means for exhausting the exhaust from said enginefree from NO₂.

Additionally, the above objects may typically be achieved by animprovement in an internal combustion engine characterized by aninternal combustion engine including at least one combustion chamber; asource of hydrogen; and a first conduit means providing communicationbetween said source of hydrogen and the combustion chamber forintroducing hydrogen into the combustion chamber.

The above object may typically be achieved by method for treatingexhaust emissions comprising the steps of providing an internalcombustion engine including an exhaust gas converter for capturing NO₂;providing a source of hydrogen; causing the hydrogen to enter theexhaust gas converter, whereby the NO₂ contained therein is converted toN₂; and exhausting the exhaust from said engine free from NO₂.

BRIEF DESCRIPTION OF THE DRAWINGS

The above objects and advantages of the invention will become readilyapparent to those skilled in the art from reading the following detaileddescription of an embodiment in the light of the accompanying drawings,in which:

FIG. 1 shows a flow diagram of a shaft power path and a waste power pathof an internal combustion engine employing an on-board electrolyzer inaccordance with an embodiment of the invention;

FIG. 2 shows a list illustrating the benefits of employing theelectrolyzer shown in FIG. 1 in an internal combustion engine; and

FIG. 3 shows a cross section of a combustion chamber of an internalcombustion engine in accordance with another embodiment of theinvention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT OF THE INVENTION

The following detailed description and appended drawings describe andillustrate various exemplary embodiments of the invention. Thedescription and drawings serve to enable one skilled in the art to makeand use the invention, and are not intended to limit the scope of theinvention in any manner. In respect of the methods disclosed andillustrated, the steps presented are exemplary in nature, and thus, theorder of the steps is not necessary or critical.

Referring to the drawings, and more particularly FIGS. 1 and 2, there isshown a system 10 incorporating the present invention along with a listillustrating the benefits achieved by the system 10. The system includesan internal combustion engine 12 having two primary power paths: 1)shaft power, and 2) waste power. The system 10 can be used with variousengine types, including but not limited to diesel fueled internalcombustion engines and gasoline fueled internal combustion engines.

Considering the waste power path, the exhaust gases are employed todrive an alternator 14 which, in turn, powers an on-board electrolyzer16 for producing hydrogen (H₂) and oxygen (0₂). Considering the shaftpower path, a belt driven alternator 18 powers the on board electrolyzer16 for producing hydrogen and oxygen.

As used in exhaust emissions treatment, the hydrogen produced by theelectrolyzer 16 is introduced as a reducing agent to an exhaustafter-treatment 20 which typically includes a lean NOX trap (not shown).The NOX is trapped in the lean NOX trap during normal engine operationand is typically released when the exhaust is in absence of oxygen. Thehydrogen regenerates the NOX trap on a continuous cycle as the NOX trapapproaches a predetermined capacity. Favorable results have been foundwherein a regeneration cycle occurs approximately three to four secondsout of every 100 seconds.

It was also found that the hydrogen introduction in the exhaust gasstream by the electrolyzer 16 in gasoline fueled engines willeffectively reduce the heat-up time of the catalytic converter duringcold startup, thus improving the quality of emissions of the engine 12.

The oxygen produced by the electrolyzer 16 is employed as an oxidizingagent to effectively cause regeneration of the diesel particulate filterin diesel fueled engines converting the particulates to CO₂.Additionally, the oxygen is used as an oxidant converting NO to NO₂upstream of the lean NOX trap.

It will be appreciated that the advantages and improvements broughtabout through the utilization of the on-board electrolyzer 16 results inimproved fuel efficiency and improved quality of the resultantemissions. As used in fuel improvement, the hydrogen (H₂) produced bythe electrolyzer 16 may be utilized with the fuel to improve operation,reduce fuel consumption, or reduce emissions.

More specifically, the on-board production of hydrogen by theelectrolyzer 16 may be beneficially used to improve operation of abio-diesel internal combustion engine or an internal combustion engineemploying an ammonia, such as anhydrous ammonia. Such an engine is shownin FIG. 3, which shows a cross section of a combustion chamber 112 of aninternal combustion engine 110. A piston 114 is adapted to reciprocateby a connecting rod 116 which is connected to an associated crank shaft(not shown).

A source 118 of anhydrous ammonia (NH₃) is fed into the combustionchamber 112 by means of an associated conduit means.

The engine 110 is further provided with an antechamber 120 for receivinghydrogen from an appropriate source, such as the electrolyzer 16discussed above, in communication with the antechamber 120. Theantechamber 120 is in communication with the combustion chamber 112 ofthe engine 110 permitting the introduction of hydrogen. A spark plug orglow plug (not shown) is disposed within the antechamber 120.

In operation, the hydrogen is caused to be ignited by the spark plug orglow plug, causing the pressure and temperature of the hydrogen in theantechamber 120 to rise. This condition causes the hydrogen to issuefrom the antechamber 120 into the combustion chamber 112 of the engine110 as a stream of hot gas. The hot gas then interacts with theanhydrous ammonia in the combustion chamber 112 of the engine 110. Theinteraction causes combustion of the anhydrous ammonia, whichconsequently forces the piston 114 of the engine 110 to be thrustdownwardly to complete the combustion stroke of the engine 110.

As a supplement to hydrocarbon fuel, hydrogen produced by theelectrolyzer 16 can improve idle operation and militate against carbondeposits in bio-diesel fueled engines and reduce fuel consumption andemissions in gasoline fueled engines.

As a substitute for hydrocarbon fuel in diesel fueled engines, hydrogenproduced by the electrolyzer 16 can reduce fuel consumption, improvecold start operation, and reduce emissions while running in idle mode.In gasoline fueled engines, the substituted hydrogen can reduce fuelconsumption and reduce emissions in cold start operation.

From the foregoing description, one ordinarily skilled in the art caneasily ascertain the essential characteristics of this invention and,without departing from the spirit and scope thereof, can make variouschanges and modifications to the invention to adapt it to various usagesand conditions.

1. A system for treating exhaust emissions comprising: an internal combustion engine including an exhaust gas converter for capturing NO₂; a source of hydrogen; means for directing the hydrogen to the exhaust gas converter for converting the NO₂ therein to N₂; and means for exhausting the exhaust from said engine free from NO₂.
 2. The system for treating exhaust emissions according to claim 1, wherein said source of hydrogen is an on-board electrolyzer.
 3. The system for treating exhaust emissions according to claim 1, wherein said internal combustion engine includes a source of anhydrous ammonia.
 4. The system for treating exhaust emissions according to claim 3, further comprising a first conduit means providing communication between the source of anhydrous ammonia and a combustion chamber for introducing anhydrous ammonia into the combustion chamber.
 5. The system for treating exhaust emissions according to claim 4, further comprising a second conduit means providing communication between said source of hydrogen and the combustion chamber for introducing hydrogen into the combustion chamber, the second conduit means including means for causing combustion of the hydrogen to react with the anhydrous ammonia in the combustion chamber of the engine.
 6. The system for treating exhaust emissions according to claim 1, further comprising a source of oxygen and a means for directing the oxygen upstream of the exhaust gas converter for converting the NO therein to NO₂.
 7. An improvement in an internal combustion engine characterized by: an internal combustion engine including at least one combustion chamber; a source of hydrogen; and a first conduit means providing communication between said source of hydrogen and the combustion chamber for introducing hydrogen into the combustion chamber.
 8. The improvement in an internal combustion engine according to claim 7, further comprising a source of anhydrous ammonia and a second conduit means providing communication between the source of anhydrous ammonia and the combustion chamber for introducing anhydrous ammonia into the combustion chamber.
 9. The improvement in an internal combustion engine according to claim 8, wherein the first conduit means includes means for causing combustion of the hydrogen to react with the anhydrous ammonia in the combustion chamber of the engine.
 10. The improvement in an internal combustion engine according to claim 7, wherein said source of hydrogen is an on-board electrolyzer.
 11. A method for treating exhaust emissions comprising the steps of: providing an internal combustion engine including an exhaust gas converter for capturing NO₂; providing a source of hydrogen; causing the hydrogen to enter the exhaust gas converter, whereby the NO₂ contained therein is converted to N₂; and exhausting the exhaust from said engine free from NO₂.
 12. The method for treating exhaust emissions according to claim 11, wherein the source of hydrogen is an on-board electrolyzer.
 13. The method for treating exhaust emissions according to claim 11, further comprising the steps of providing a source of oxygen and directing the oxygen upstream of the exhaust gas converter for converting the NO therein to NO₂. 